An electric motor of the generic type is known from CH 337 267. The electric motor has a double-walled housing that is embodied as a welded construction. The laminated core of the stator lies against the inner wall of the housing. As a consequence, it is difficult to position and centre the stator in the housing. On account of the inner wall of the housing being a load-bearing part of the housing, the wall requires to be amply dimensioned, which impairs the transfer of heat. Overall, the housing requires a large amount of installation space.
DE 37 36 159 A1 discloses an electric motor of a plunger pump that has a vertical axis, but does not have a double-walled housing. The single housing wall is a tube that is shrunk onto the laminated core of the stator, and in one embodiment has a thicker wall thickness at both ends and is connected in each case to an end plate. The single housing wall is surrounded by the water that is to be pumped. On account of the tube being a load-bearing part of the housing, it is necessary for the thickness of the wall of the tube to be dimensioned accordingly.